Casein kinase II phosphorylates Ser468 in the PEST domain of the Drosophila IκB homologue cactus

FEBS Letters

Gay, Nicholas J¹  Kubota, Ken¹  Parker, James¹  Packman, Leonard C¹ 

[1] Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK

关键词: IκB cytoplasmic anchor protein;    Casein kinase II phosphorylation;    Protein stability;   

DOI  :  10.1016/S0014-5793(96)01324-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cactus protein is a Drosophila homologue of the mammalian IκB family of cytoplasmic anchor proteins. In unstimulated cells they function to retain rel/NFκB transcription factors in the cytoplasm but are rapidly degraded in response to signalling. The destruction of cactus or IκBα allows the rel/NFκB transcription factor to relocalise to the nucleus. Cactus is a phosphoprotein and has in its C-terminus a PEST protein stability domain. In this paper we show that, like mammalian IκBα, the PEST domain of cactus is phosphorylated by casein kinase II. We have localised the site of modification to a single residue, Ser⁴⁶⁸, and find no evidence for additional phosphorylation sites. The conservation of these sites in mammalian and invertebrate cytoplasmic anchor proteins suggests that phosphorylation by casein kinase II may play a critical functional role, plausibly in the regulation of constitutive or inducible proteolysis.

【 授权许可】

Unknown